Why lower one’s blood pressure if the heart is working at 25% capacity?

Submitted by Gil from Illinois on 03/26/2015

The primary function, the only function, of the heart is to provide FLOW to the vital organs of the body such as the brain, kidneys, gut, and muscles. Flow is a physical function described by Ohm’s Law: flow=pressure/resistance. in the normal state, during exercise the flow is increased primarily by increasing the pressure. The failing heart is unable to increase the pressure appropriately. In this situation, the only way to increase (or maintain) flow is by decreasing the resistance. Put another way, for a given amount of squeeze, the amount of flow increases at a lower resistance. This is especially important in a weak heart with an ejection fraction of 25%. By lowering the resistance, the ejection fraction (flow) can be increased. I hope this answers your question.